Needle sharpening device



Dec.`2, 1941. F. A. s'rAlNBRooK 2,254,598

NEEDLE SHARPENING DEVICE Filed Nov. 24, 1939 Patented Dec. 2, 1941 lUNITED STATES PATENT olf-Ficsl Application November 24, 1939, serial No. 305,907

2 Claims.

This invention relates to a sharpening device for phonograph needles of the thorn type. Thorn needles are desirable for purposes of tone quality but they need frequent sharpening.

It is anobject of the present invention to provide needle-sharpening means which can be voperatedrwith minimum difficulty and bother but which will eiTectively and quickly sharpen such needles.

Such means may consist of a member having an abrasive face removably mounted on the rotating platen and spindle of a phonograph, and a needle-holding device by which the pointed end portion of a needle is held laterally against the abrasive surface and is driven by movement of the phonograph spindle to rotate in a direction opposed to the movement of the abrasive surface with which it is in contact.

For a more complete understanding of the invention, reference may be had to the description thereof which follows and to the drawing of which Figure l is a perspective view of an embodiment of the invention mounted upon a phonograph platen.

Figure 2 is a fragmentary elevational View of the same, on a larger scale, partly in section.

Figure 3 is a section on the line 3 3 of Figure 2.

Figure 4 is a perspective View of the parts of the chuck shown in Figure 2.

Figure 5 is an elevation, with parts broken away to show in section, of a modified form of the invention.

In Figure 1 the rotatable platen or table of a phonograph is indicated at I0, such platen being customarily carriedon a vertical spindle I2 by which it is driven. A support member I4 is removably mounted on the central portion of the platen, this support member preferably comprising a cylindrical block of rubber or other suitable material having a central recess or socket I6 in the under face thereof adapted to receive the upper portion of the spindle I2 with a frictional t so that the support member I4 will rotate with the spindle I2. Alined with the recess I6 is a second recess I8 in the upper `face of the member I4, this recess preferably having mounted therein a cylindrical bearing member 2D which rotates therewith. The bearing member 20 is preferably made of metal or some suitable plastic and is provided with a central recess 22 which is flared as at 24 at its upper end. On the top of the member I4 is an abrasive surface 26 of ne sandpaper, emery paper or any other equiv- 36 of a shaftat one end of which isvmounteda coaxial Wheel 38 preferably having a rubber tire 40 on its rim. At the other end of the shaft is a chuck 42 which, as shown in Figure 4, may

have a plurality of stiff jaws 44 surrounding a central bore 46 which is adapted to receive and to grip frictionally the butt end of a phonograph needle. If desired, the natural resilience of the fingers 44 may be reinforced by a spring 48 which surrounds the fingers, being seated in a groove 50. A needle 52 is indicated in Figure 2 inserted in the chuck 42.

The upper portion of the stem 30 may comprise a handle member 54 in which is embedded a coaxial screw 56. This screw is in threaded engagement with the sides of the slot 34 so that the vertical clearance for the shaft 36 within the slot 34 may be regulated by rotation 0f the handle 54. The screw 56 may be held in any position of adjustment by a locknut 58.

In operating the device, a phonograph needle is thrust into the bore 46 of the chuck 42 and isl thereupon frictionally held therein. The spindle I2 with the support member I4 thereon is permitted to rotate under the action of the spring or motor -Which is employed to drive the spindle. The needle-holding device is then placed in position by thrusting the lower end 32 of the stem 30 into the recess 22 and pressing the device down gently so that the wheel 38 is driven by frictional contact with the friction surface 26 at one side of the axis of the spindle I2. This rotates the needle 52 the pointed end portion of which is laterally pressed against the friction surface at the opposite side of tlie spindle axis. Hence the portion of the needle which is in contact with the friction surface revolves in a direction opposite to the motion of that portion of the surface, and the needle is quickly and accurately sharpened.

If preferred, the whole device may be made in a unit such as is illustrated in Figure 5. To support an abrasive surface, a thimble 60 of metal or suitable plastic is provided. A rubber socket element 62 is forced into the open lower end of the thimble to be held therein frictionally, The element 62 is adapted to fit frictionally over the spindle I2 of a phonograph. At the upper end of the thimble is an opening 64 through which the reduced lower end portion 66 of the stem 58 loosely fits. A nut 10 threaded on the end portion 66 keeps the thimble assembled to the stem 68 but permits limited axial movement of the stem relative to the thimble. A metal disk 12 is secured to the upper end of the thimble 6,0, this disk having struck-up tongues 14 which engage the inner edge of a ring or annular 16 having an abrasive face 18 so as to hold the ring releasably in position for use.

The stem 68 is drilled to form atapered holev 80 for the shaft 36 which carriesthechuck A2M- and the driving wheel 38. When the handle 5@ is pushed downward, the needle is pres'sd'aginst the abrasive surface of the ring 16 and is rotated by the driving wheel 38 which is also'pressed against the opposite'portion of the same ring'. When the device is lifted, the needle 52 is lifted welVabove the'surfacel'of the ring, such lifting movement being limited by engagement of the nutY 'I0 with the upper end of the thimble Sl. Thereupon thewhole device is liftedfrom the spindle `I2, andthe needle 5 2 can quickly and easily b'e replaced in the chuckby another needle to be sharpened. i l

It is -evident that various modifications and changes may be made in the embodiment of the invention herein shownand described without departing from the spirit or scope thereof as defined infthe fllowing claims.

I claim:

1. A phonograph needle sharpening device comprising a circular plate having a, central opening, a tubular thimble secured to the under face of said plate and extending downward therefrom, a socket element of frictional material in the lower end of said thimble and adapted for frictional engagement over the spindle of a phonograph, a ring of abrasive material on the margin of the upper face of said plate, a stem projecting through said opening' into said thimble, means on the lower end of the stern normally preventing removal thereof through the opening, a handle at the upper end of said stem, a shaft extending transversely through said stem and rotatable therein, and a Wheel and a chuck for needles at the respective ends of said shaft.

2; A phonographY needle sharpening device comprising a circular plate having a central opening, a tubular thimble secured to the under face of said plate and extending 'downward therefrom, a'socket element 'of frictioal material in the lower end of said thirnble and adapted for frictional engagement over the spindle of a phonographfa ring of :abrasive material on'the margin of the upperf face of 'said plate, a stemfprojecting throughsai'd 'opening' into said thinible.

a handle at the upper end of said stem, a shaft extending transversely through said stem and rotatable therein, and a wheel and a chuck for needles at the respective ends of said shaft.

.FOREST A; s'rArNBRooK. 

